1. Field of the Invention
The invention relates to a process and a device for correcting geometric errors in the transfer of information to a printing stock.
2. Description of the Related Art
The transfer of information to a printing stock is performed by a printing machine that has one or more digital imaging units, which are used for the depiction of the information. For imaging, machine-dependent digital matrix data, such as those produced by a screen image processor, are required. For each color to be used, the screen image processor generates a matrix of digital data intended for the printing mechanisms with the given imaging units. The imaging units can print directly on the paper such, for example, as inkjet printers, via several intermediate steps such, for example, as electrophotography, or by first producing a permanent printing form such as in offset printing.
Processes for digitally imaging a printing form which include compensation for imaging-related errors are known (see U.S. Pat. Nos. 5182990, 5453777, and 5174205). In these processes, geometric errors caused by the printing machine or the printing process with its materials are compensated for by mechanical intervention on the printing form itself. If the possibilities for such intervention are limited, for example, by a rigid printing form such as that used in the erasable computer-to-press process, the possibilities of mechanical intervention are not available.
Geometric errors occur during the imaging of films, during the use of printing plates and printing cylinders, as well as during the use of printing machines, printing processes and with various materials used. These geometric errors reduce the quality of the printed product.